What is the function of the software eject button in multimedia control buttons on TX series VAIO computers?

Function of the software eject button in multimedia control buttons.

The software eject button is used to conveniently eject the optical driver in Windows® XP or in Instant mode. Even in the ODD mode, the button can also eject the optical driver when the power is turned off. This way, the software eject button can be used to power on the optical driver in ODD mode.